The growth and properties of Au oxide films formed on an Au electrode in a 0.1-1.0 M NaOH solution were investigated using potentiostatic and cyclic voltammetric techniques. Scanning electron microscopy images showed the structure of an Au oxide film on an Au electrode at various oxidation potentials: 1.5, 2.0, 2.5, and 3.0V. The Au oxide electrode was used to determine oxidation potential of heterocycles thiazole in phosphate buffer (pH 2.21). The potential peaked at 0.54V for rhodanine, 0.40 V for thiazolidine-2,4-dione, 0.47V for thiazolidine, and 0.48 V for L(-)-thiazolidine-4-carboxylic acid. Compared with the results obtained from an Au oxide electrode, the peak potential of heterocycles thiazole was less positive and the peak current 3-15 times higher than that of the peak potential found using a bare gold electrode. (C) The Electrochemical Society of Japan, All rights reserved.
